Wireless Sensor NetworksCS 4501

Professor Jack StankovicDepartment of Computer

Science

Fall 2010

Ad Hoc Wireless Sensor Networks

Ad Hoc Wireless Sensor Networks

• Sensors• Actuators• CPUs/Memory• Wireless Radio• Power Limited

Self-Organizing

Mica2 and Mica2DotMica2 and Mica2Dot

• ATMega 128L 8-bit, 8MHz, 4KB EEPROM, 4KB RAM, 128KB flash• Chipcon CC100 multi-channel radio (Manchester encoding, FSK).

From 10-20 ft. up to 500-1000ft.

Sensor BoardSensor Board

Exciting PotentialExciting Potential

• Will affect all our lives!• The next Internet!

• MANET (mobility)• WSN (sensing)• Swarms (scale)

• Pervasive Computing• Cyber Physical Systems

Wireless

Body Sensor Technology Commercially Available Body Sensor Technology Commercially Available

Galvanic skin response and pressure-sensitive smart shirt that senses anxiety

Sonar Jacket to detect objects for the blind

Climate-sensitive Dress senses levels of CO2

Body Sensor Technology Commercially AvailableBody Sensor Technology Commercially Available

Pedometer”in Nike shoe gives distance, pace, calories burned during run – interfaces with iPod, iPhone

Babyglow clothes change color when your baby has a temperature!

Heart rate monitors that interface with iPhone

Northface jacket that senses and adjusts body temperature

Exciting PotentialExciting Potential

• The Internet Gets Physical

• “Sensing technologies will be one of the hallmarks of this century”

• 1980 => decade of microcomputers

• 1990 => decade of the Internet• 2000 => decade of WSN

Global Sensor NetworksGlobal Sensor Networks

Internet

LocalTransportProtocol

LocalTransportProtocol

ProgrammingStation

Server Server

Nodes Nodes

Omnix PhysicalNetwork

Omnix PhysicalNetwork

The Physicalnet

Purpose of this Course (1)

Purpose of this Course (1)

• Learn key ideas, principles, solutions and open research questions

• Get you to think differently– Decentralized algorithms– Swarms -> Aggregate behavior– Spatial (geographic) – Temporal (real-

time)– Minimum capacity devices

• New system constraints

– Environment interaction• Real-time systems

Purpose of this CoursePurpose of this Course

• Hands on experience with WSN• Learn to program such

devices/systems

• Practical: Start your own company?

Purpose of CoursePurpose of Course

• More like a real job– Not single topic (let’s study calculus,

Java, etc.)• Multi-disciplinary

– Not solely from a textbook • New HW, new language, new tools, new

concepts, …

– There will be significant material presented in class that is not in the reading

Course Outline (1)Course Outline (1)

• Introduction– Logistics and Motivation

• Sensors and Hardware• Wireless Communications• How to Program

– NesC, TinyOS and TOSSIM

• MAC protocols (B-MAC and MMAC)

Course Outline (2)Course Outline (2)

• Routing (geographic based; multi-hop)– GF, DSR, AODV, DD, SPEED, RAP, IGF

• Clock Synchronization• Localization• Power Management• Programming Abstractions• Application to Home Health Care• Summary

LogisticsLogistics

• Prerequisites: – Networking (recommended)– OS and architecture helpful– Need to know C (or learn on your own)

• Reading– Text

• H. Karl and A. Willig, Protocols and Architectures for Wireless Sensor Networks, Wiley, 2007.

– Papers from the literature

LogisticsLogistics

• Grading– Homework - 10%– Exam 1 - 20%– Exam 2 - 20%– Programming Assignments – 40%– Final Homework – 10%

LogisticsLogistics

• Labs (Room 002a)

– L0: Intro (no credit, necessary for all labs)• Compile, link, download, run• Mechanics

– L1: Simple Sensing and Actuating – 10%– L2: Wireless Communications – 10%– L3: Synchronization – 10%– L4: Flash Memory and Queries – 10%

LogisticsLogistics

• Class – M. – W. 2-3:15

• Location – MEC 341

• Office Hours (may change)• By appt• M 1-2• W 3:30-4:30

• TA – tbd• Web Page

– http://www.cs.virginia.edu/~cs451

LogisticsLogistics

• URL of interest– http://webs.cs.berkeley.edu/tos

More Motivation• 1998

– 100 million processors f or workstations– 6.4 billion f or embedded systems– approximately - 2% for workstations

• 2006– approximately 0% for workstations

• Ubiquitous computing (seemless, invisible, pervasive, amorphous, …)– wireless sensor networks

• HP Announces – trillions of sensors to create a worldwide central nervous system

The field is exploding

Application Spectrum Application Spectrum

Hazard Detection

Biological Monitoring

MedicalDomain

Smart Environment

Wearable Computing

Transportation

Earth Science & Exploration

Context-Aware Computing

Interactive VR Game

Wireless Sensor Networks

Urban WarfareMilitary Surveillance

Disaster Recovery Environmental Monitoring

More Applications More Applications

• Location Services• RFID• Integrate mobile phones, RFID,

sensor nets, Internet

• Universal Device (mobile phone with sensors, computing, …) ??

• Cyber Physical Systems